Bated on the paleogcomagnetum ot the sediments derived from drilling cores in the Jiao-zhou Bay and the 14C-dating, combined with the analyses of the paleomicrobiology, spore-pollen, grain size and ainino acid, the following results are obtained:(ⅰ) Structural fractures formed the framework for the Jiaozhou Bay. (ⅱ) jiaozhou Bay was a continental basin during the low tea level of the glacial period in 20000-11000 yr BP. (ⅲ) Sea level rose again, thus forming the initial Jiaozhou Bay during the poit-glacial period since 11000 yr BP. (ⅳ) Distribution of the sub-marinf relief of the Jiaozhou Bay was finally formed due to the reconstruction of As tidal current and the fluvial hydrodynamical actions, (ⅴ) It can be estimated that the Holocene of the jiaozhou Bay began at 11000 yr BP on the basis of the comparison between the sedirnental characteristics of the Jiaozhou Bay and that of the Huaoghai Sea.